To use these commands in your own courses you will need to include PGML.pl in your loadMacros() segment. Start the display of your problem text with BEGIN_PGML which expands to

TEXT(PGML::Format2(<<'END_PGML'));

and end with END_PGML. These are used instead of the usual BEGIN_TEXT/END_TEXT construction. You can use both BEGIN_TEXT/END_TEXT and BEGIN_PGML/END_PGML in the same problem, if you wish. See SampleProblem4 for an example (with explanation) that uses PGML.